The invention relates to a modular railway rake constituted by modules in the form of so-called xe2x80x9cdouble-deckerxe2x80x9d vehicles (each having two superposed levels and an intermediate level providing access to the vehicle), and to a railway train made up of such rakes.
More particularly, the object of the invention is to create modular rakes and trains of the above kind which are comfortable for passengers and which, whatever their composition, have masses that are approximately equally distributed along the entire length of the rake or train, performance which is practically identical from one rake or train to another, and a good return on investment for the transport authority.
It is known that modular design enables highcapacity rakes and trains to be made up when there is a heavy demand for transport, especially if the modules are of the double-decker type, and avoids the use of rolling stock with a greater capacity than is really needed when demand is low, without this flexibility of operation requiring very high investment by the transport authority. Note that passenger comfort implies that passengers have sufficient room, which requires the ability to increase capacity in a regular manner, i.e. the space available for passengers must be approximately the same in all of the modules.
Also, for the rake or train to have good dynamic behavior, and to limit track wear, axle loads must be as similar as possible; for reasons of reliability and safety, it is also necessary for on-board mechanical or electrical equipment to be operated away from its performance limits (not only in terms of axle load, but also in terms of electrical power transmitted and dissipated, electrical insulation, etc.); such equipment must therefore be distributed in the most appropriate manner, rather than being reduced in quantity and/or in volume without due consideration; the solution generally adopted in the case of single-decker vehicles, which consists in distributing the equipment along the vehicle, for the most part in compartments under the passenger compartment, is inapplicable in the case of double-decker vehicles as it would produce vehicles that are very tall and unstable and that would not fit under existing loading gauges. The equipment must be distributed without unduly affecting passenger capacity, without compromising the comfort of passengers, including the comfort of handicapped passengers, by reducing the space allocated to each of them or by impeding access to the seats and to the various facilities (bar, toilets, baggage space), and without impeding the movement of personnel along the rake; distribution must also be compatible with having different vehicles all based on a single body structure. The invention also aims to solve these problems.
It is also known that adding or removing vehicles can affect the performance of the rakes or trains, because of the resulting variations in motive power, and that this can require the speeds of all the rakes and of all the trains in circulation to match the speed of the slowest rake or train, which is normally the rake or train having the lowest ratio of motive power to load; the invention aims to provide modular rakes and trains which do not suffer significantly from this drawback. Hereinafter, the motive power of a vehicle or a group of vehicles is expressed by a xe2x80x9cmotive power factorxe2x80x9d which is equal to the ratio of the number of driving axles to the total number of axles of the vehicle or of the group of vehicles.
Also, as already mentioned, although modularity keeps down the investment required of the transport authority by offering the ability to match offer quickly to fluctuations in demand by means of a relatively small number of vehicles, reducing the investment required of the transport authority is not the only point to be taken into consideration in order to obtain a good return on investment: given the cost and service life of the vehicles, obtaining a good return on investment also implies good long-term adaptability so that the transport authority can vary its offer at low cost over a long period whenever forecasts turn out to be incorrect, or whenever market or rail infrastructure trends require modification of the rolling stock. It is therefore necessary to ensure that vehicle standardization does not constitute an obstacle to their evolution or to the possibility of deriving a sufficient number of variants from the same body structure to enable the fleet to be adapted at low cost both in the short term and in the long term.
The object of the invention is to remedy the drawbacks of prior art rakes and trains and to satisfy the conditions referred to above to the greatest possible extent.
To this end, the invention provides a modular railway rake formed of at least two vehicles with two superposed levels, including at least one bogie including at least one driving axle, at least one bogie including at least one carrying axle, and on-board equipment including at least one power supply electronic unit for supplying motive power to one or more traction motors, at least one motive power supply unit for supplying power to the electronic unit, at least one auxiliary power supply unit for supplying power to auxiliary equipment, and at least one device for connection to an overhead power supply network, in which rake the motive power factor of a vehicle or a group of vehicles is defined as the ratio of the number of driving axles to the total number of axles of the vehicle or group, wherein at least one vehicle includes at least one bogie including at least one driving axle and at least one bogie including at least one carrying axle, at least one bogie of the rake including at least one carrying axle is associated with at least one of said on-board equipment items disposed approximately over that bogie, and the ratio between the respective motive power factors of any two groups of two vehicles of the rake is not less than ⅓ and not more than 3.
By virtue of the above features, a rake including only two vehicles already has the motive power suited to the number of passengers that it can transport and is not largely over-powered, in the usual way, in order to be enable non-motorized vehicles to be added to the original two vehicles, and the total load can be made very similar at most of the bogies, if not all of them.
The rake in accordance with the invention can also have one or more of the following features:
at least one bogie including at least one driving axle includes two driving axles;
at least one bogie including at least one carrying axle includes two carrying axles;
at least one power supply electronic unit is disposed approximately over a bogie including at least one driving axle;
at least one power supply electronic unit includes at least one inverter and is disposed in the roof of the vehicle;
a rheostatic braking system is disposed approximately over at least one bogie including at least one driving axle;
at least one power supply unit is disposed approximately over a bogie including at least one carrying axle;
at least one motive power supply unit includes at least one electrical transformer;
at least one motive power supply unit includes at least one choke;
at least one bogie including at least one carrying axle is associated with at least one power supply unit and one device adapted to be connected to an overhead electrical power supply network and disposed approximately above that bogie;
it includes at least one interposed vehicle with two superposed levels between two end vehicles and said interposed vehicle includes a bogie including at least one driving axle and a bogie including at least one carrying axle;
the bogie including at least one driving axle of at least one interposed vehicle includes two driving axles;
the bogie including at least one carrying axle of at least one interposed vehicle includes two carrying axles;
it includes another interposed vehicle with two superposed levels between two vehicles and including two carrying bogies;
it includes an interposed vehicle with two superposed levels between two end vehicles and including two bogies, one of which includes two driving axles and the other of which includes at least one driving axle; and
it includes an interposed vehicle with two superposed levels between two end vehicles and including two bogies, one of which includes two carrying axles and the other of which includes at least one carrying axle.
Accordingly, adding vehicles between the two end vehicles is accompanied by an approximately proportionate increase in passenger capacity and in motive power, and as from a particular level of motive power, this even allows a non-motorized vehicle to be added without leading to the rake being significantly underpowered.
The invention also provides a railway train including at least two rakes as defined hereinabove connected by removable coupling means.
It is therefore possible to create a high-capacity train from a small number of vehicle designs.